The Premier League season may not start until Aug. 16 but Arsenal and Manchester United are already reportedly going head-to-head—in the race to sign German World Cup winner Mats Hummels.

United's interest in the Borussia Dortmund defender has long been documented in this transfer window, with the Mirror one of the latest to fuel speculation of a move to Old Trafford. But that has not stopped Gunners boss ArseneWenger from assessing a move for the player too, according to Metro.

The 25-year-old's club have always insisted that he is not for sale, but there is a growing belief that Hummels will be allowed to leave the Westfalenstadion this summer, and Wenger wants in on the action.

United boss Louis van Gaal has been making all the running for Borussia Dortmund defender Hummels and, despite insistences from his club that he is going nowhere, there is a belief that the player may be available for £30 million.

And it is understood that the Londoners (Arsenal) will not allow the Old Trafford giants' interest in the 25-year-old to go unchallenged.

It is unusual for Wenger to take on United, or any of the Premier League's big six, in the transfer market. But having talked at the weekend about Arsenal's improved title chances in what he expects to be a very close battle this season, per Gary Jacob of The Times, the Frenchman is now flexing his muscles.

And in a straight-out battle with United, Wenger has much in his favour.

His £100 million transfer kitty is still going strong it seems. The club have the kudos of already landing Chile's World Cup star Alexis Sanchez from Barcelona this summer and can also offer Hummels the chance to join up with fellow German World Cup winners MesutOzil, Per Mertesacker and Lukas Podolski at the Emirates.

The Frenchman can also offer Champions League football—something Van Gaal and United can't—and that could be the best bargaining chip of all.

Markus Schreiber/Associated Press

Wenger has already stated that Belgian centre-back Thomas Vermaelen could leave the Emirates this summer, as reported by Reuters, and with United and Barcelona sniffing around the former Ajax player, that nugget of information could have a double effect.

Firstly, it would make room in the squad for a new arrival such as Hummels. Secondly, it increases United's interest in a deal for the 28-year-old defender, who has been rejecting talks over fresh terms at Arsenal, according to James Dickenson of the Express.

All this reported transfer manoeuvring is a real statement of intent from the Gunners. After years of being viewed as a selling club, the time appears to have arrived when they are willing to take on their rivals in the transfer market.

If Arsenal sign Hummels & sell Vermaelen to Barcelona, it'll be the greatest summer of transfer business by Arsene Wenger EVER.